[R] Problems with coxph and survfit in a stratified model with interactions

rm rm at wippies.se
Sat Oct 13 22:52:23 CEST 2012

I’m trying to set up proportional hazard model that is stratified with
respect to covariate 1 and has an interaction between covariate 1 and
another variable, covariate 2. Both variables are categorical. In the
following, I try to illustrate the two problems that I’ve encountered, using
the lung dataset.

The first problem is the warning:

To me, it seems that there are too many dummies generated.

The second problem is the error:

View this message in context: http://r.789695.n4.nabble.com/Problems-with-coxph-and-survfit-in-a-stratified-model-with-interactions-tp4646095.html
Sent from the R help mailing list archive at Nabble.com.

More information about the R-help mailing list